Process variation is an increasingly important factor in the design of high yielding and high-performance ICs. Manufacturing lines use scribe line parametric measurement macros to measure technology parameters such as threshold voltages, resistances, currents, oxide thickness, resistance, capacitance, and composite measurements. The measurements obtained from scribe line parametric measurement macros are affected by other macros placed close to the scribe line (proximately effects). Different manufacturing lines use different scribe line measurement macros. Since the same product or a set of products produced from a common design system are manufactured in multiple lines, the capability to match performance, power, and functionality between multiple manufacturing lines is needed. Controls are needed so that the output of the multiple lines results in the same outcome (power, performance, functionality, etc.) when said products are used in systems.
Process variation in IC fabrication is the deviation from intended or designed values for a structure or circuit parameter of concern. Process variation can result in the fluctuation of parameter values and dimensions in both the structural device and interconnect levels, which can influence performance of ICs.
Conventionally, manufacturing lines use embedded devices in the scribe line of a semiconductor to verify that products meet specifications. The embedded devices can be tested during the manufacturing process and measurements taken from the devices can be compared to technology design rules. Scribe line measurement structures are affected by design of the structure and placement within the scribe line (use of fill shapes, proximity to adjacent structures, etc.). Scribe line measurements are used as product acceptance criteria in many foundry engagements. Since each manufacturing line may use different scribe line structures, the same product design manufactured in multiple manufacturing lines using the same design rule specification can create product that has different functionality, performance, and power.
However, this can result in product that differs substantially in the end system application. As such, different measurement structures embedded in the product die are also used to test a product manufactured in one manufacturing line and to determine that the final product meets functionality, performance, and power requirements. As a result, it is difficult to qualify multiple manufacturing lines to produce the same product with equivalent functionality, power, performance, and yield even when the same technology design rules are applied.
Moreover, the use of conventional scribe line test structures to qualify a manufacturing process line does not guarantee that a product is operable. Conventional manufacturing processes test products using a scribe line test structure, and when the final products are compliant with expected measurements, the final products are distributed to customers. However, the same products produced on different manufacturing lines differ from one another. More specifically, a product design can be manufactured on several different manufacturing lines, but due to process variations on these manufacturing lines, the products are not identical. As a result, these products do not necessarily operate in the same manner. Products designed with the same design system are expected to match the outcome predicted by the design system and are subject to the same issues as a common product manufactured in multiple manufacturing lines.
Accordingly, there exists a need in the art to overcome the deficiencies and limitations described hereinabove.